Method for monitoring the state of a tube for a coating in a system of pipes or ducts

ABSTRACT

A method for monitoring a status of a sleeve for lining a system of pipes or conduits, the sleeve being impregnated with a curable resin, includes the steps of providing the sleeve, disposing at least one fiber optic sensor in thermally conductive contact with the sleeve, and generating, using the at least one fiber optic sensor, a positionally resolved thermographic image representative of a temperature of the sleeve as a function of position and time

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.12/206,515, filed Sep. 8, 2008, which claims the benefit of GermanPatent Application No. DE102007042546.7, filed Sep. 7, 2007, both ofwhich are incorporated herein by reference in their entirety.

BACKGROUND

The present invention relates to a method and system for monitoring thestatus of a sleeve for a lining in a pipe system or conduit system.

BRIEF SUMMARY

It is an aspect of the present invention to provide a method formonitoring a sleeve for a lining of a pipe system or conduit system,which method is performable over a long period of time, measurementsbeing possible at one point in time and/or in arbitrarily repeatablefashion over time.

According to the invention, a method for monitoring a status of a sleevelining in a pipe or conduit, wherein the sleeve comprises a curableresin, comprises the steps of disposing a fiber optic sensor arrangementin thermally conductive contact with the sleeve, wherein the fiber opticsensor arrangement is configured to sense the temperature of the sleevealong multiple positions along the length thereof curing the curableresin over a period of time; during the curing act, generating, usingthe fiber optic sensor arrangement, positional and time-related measureddata of the temperature thereof. The act of generating positional andtime-related measured data is performed using a positionally distributedtemperature sensing system.

In one embodiment, the act of generating positional and time-relatedmeasured data is reiterated during the curing act.

In another embodiment, the act of generating positional and time-relatedmeasured data of the temperature of the sleeve is repeated throughoperating period of the sleeve.

In another embodiment, the curing quality of the sleeve is verifiedalong length of the sleeve following the act of generating positionaland time-related measured data of the temperature of multiple positions.In another embodiment, the positional and time-related measured data ofthe temperature of the sleeve can be recorded. Further, the positionaland time-related measured data of the temperature of the sleeve can bedepicted. In addition, the depiction can represent positional andtime-related measured data of the temperature at a positional resolutionbelow 1 m. Further, the depiction of the positional and time-relatedmeasured data can represent selected positions along the sleeve. Inaddition, the depiction of the positional and time-related measured dataalong the sleeve can be a function of time. In a preferred embodiment,the depiction of the positional and time-related measured data can be a3-dimentional representation.

In another embodiment, the positional and time-related data can becorrelated with a thermal model of the curable resin as a function ofthe degree of curing.

In yet another embodiment, the positional and time-related measured datacan be used to control the energy for the curing process.

Further according to the invention, a system configured to monitor astatus of a curable resin sleeve lining in a pipe or conduit comprises:a fiber optic sensor arrangement that includes at least one opticalwaveguide is disposed in thermally conductive contact with the sleeve.The fiber optic sensor arrangement is configured to sense thetemperature of the sleeve along multiple positions along the lengththereof. A thermal energy source or a light source is coupled to thepipe or conduit for curing the curable resin over a period of time andan evaluation apparatus is coupled to the fiber optic sensor arrangementand configured to generate, using the fiber optic sensor arrangement,positional and time-related measured data representative of atemperature of the sleeve as a function of multiple positions along thelength thereof and over a period of time.

In one embodiment, the multiple positions can be about 0.5 m to about 1m along the length of the sleeve.

In one embodiment, the fiber optic sensor arrangement can include amultimode optical fiber.

In another embodiment, the at least one optical waveguide can beembodied as an optical waveguide sensor cable.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained in further detail below withreference to several exemplifying embodiments in the Figures, in which:

FIG. 1 schematically shows an arrangement for fiber optic temperaturemeasurement during conduit rehabilitation using the sleeve liningmethod;

FIG. 1 a schematically depicts the positional situation

FIG. 1 b is a curve for temperature as a function of fiber location,with an irregularity in the base region of the liner;

FIG. 1 c is a curve for temperature as a function of fiber location,with an irregularity in the peak region of the liner;

FIG. 1 d shows OWG sensor arrangements in the longitudinal direction ofthe liner;

FIG. 1 e shows OWG sensor arrangements in the transverse direction ofthe liner;

FIG. 2 schematically depicts the process control apparatus for linercuring;

FIG. 3 shows explanations regarding liner quality

FIG. 3 a is a positional temperature curve at measurement time t;

FIG. 3 b is a curve for temperature over time at selected measurementlocations;

FIG. 3 c schematically depicts a thermographic image with reference toFIGS. 3 a and 3 b;

FIG. 4 schematically depicts the apparatus for positioning the grindingrobot;

FIG. 5 schematically depicts arrangements and embodiments of the OWGsensor;

FIG. 5 a shows examples of sensor cable arrangements between the oldpipe and the liner/slip film;

FIG. 5 b shows examples of embodiments of the OWG sensor, with referenceto FIG. 5 a;

FIG. 5 c shows examples of sensor fiber arrangements inside the liner;

FIG. 5 d shows examples of embodiments of the OWG sensor, with referenceto FIG. 5 c;

FIG. 5 e shows an example of a sensor mat arrangement with a radialinstallation direction between the old pipe and the preliner/slip film;

FIG. 5 f shows an example of a sensor mat embodiment, with reference toFIG. 5 e;

FIG. 5 g shows an example of a sensor mat arrangement with alongitudinally oriented installation direction between the old pipe andthe preliner/slip film;

FIG. 5 h shows examples of sensor mat embodiments, with reference toFIG. 5 g; and

FIG. 6 shows OWG sensor mat embodiments for water level measurement.

DETAILED DESCRIPTION

The individual method steps according to an embodiment of the presentinvention include:

producing a preferably glass-fiber-reinforced sleeve impregnated withcurable resin;

bringing at least one fiber optic sensor into thermally conductivecontact with the sleeve; and

preparing a positionally resolved thermographic image of the temperatureof the sleeve as a function of position and time, by means of apositionally resolving fiber optic temperature sensor apparatus.

The fact that thermally conductive contact is brought about produces anarrangement of a positionally distributed temperature sensor thatenables an (almost) uninterrupted measurement of the surface temperaturedistribution of the sleeve in the form of a positionally resolvedthermographic image as a function of location and time. Measurements canbe repeated over time, beginning with production (of the not-yet-curedsleeve, and transport and storage thereof), installation (curingperformed during installation) in a system, through the operatingperiod, to later repair of the liner converted by curing.

With the aid of the spatial thermographic image (hereinafter a“temperature image”), the curing process of the sleeve can be monitoredin situ and can be made available to a process management system. Afterthey are produced, sleeves are preferably stored so that they are notexposed to light and/or heat. Many manufacturers also effect cooling ofthe sleeves until they are installed. If a fiber optic sensor is alreadybrought during this phase into thermally conductive contact with asleeve, temperature monitoring can be begun in, so to speak,uninterrupted fashion from the moment of manufacture.

Upon the occurrence of unforeseeable heat evolution events inside andoutside the sleeve, process parameters can be controlled, modified,and/or adapted by way of the process management system. Processmanagement can be further optimized by incorporating a thermal modelregarding the thermal environment properties of the sleeve.

The present invention includes a testing method with which, on the basisof the temperature image, measured values can be furnished that enablean evaluation of the quality of the drainage system (hydraulics,material strength, and impermeability of the liner). By way of thetesting method, which is continuously repeatable over time, averification of correct installation (rehabilitation) can be effected atany time.

The use of, for example, fiber optic Raman temperature sensors enablespositionally resolved, distributed temperature measurement along anoptical fiber segment up to several kilometers in length. The positionalresolution achievable is between 0.5 m and 1 m; temperature accuracy is<1 K, and depends on measurement time and measurement location (range).A positional resolution of, for example, 1 m means that indicated valuecorresponds to the average temperature value of a piece of fiber 1 mlong. In other words, temperature events that occur within a portion ofthat length cannot be separated and measured exactly.

FIG. 1 shows a schematic arrangement of a lined conduit.

A depiction of the temperature profile over time and space canadvantageously be used

a) to monitor process control in terms of homogeneous curing of theliner (see FIG. 2);

b) to draw conclusions as to curing quality along the liner (see FIG.3);

c) for exact localization of defect sites, for example in order toposition grinding robots to take samples (see FIG. 4).

Discussions Follow Below Regarding

d) arrangements and embodiments for optical waveguide (OWG) sensors (seeFIG. 5);

e) further uses (synergies) of the arrangements and embodiments of theOWG sensors in the pipe and conduit sector, for fiber-optic-based

(e1) leak detection;

(e2) liquid level measurement; and

(e3) thermal image measurement.

Explanations Regarding (a) Process Management for Curing

Utilizing a dynamic thermal model, the temperature for optimum curing atany point on the liner can be calculated. The dynamic thermal model isbased on a knowledge of the thermal resistance values of the liner resinas a function of the degree of curing (which values are known fromlaboratory experiments), and on a knowledge of the thermal resistancevalues of the measurement arrangement used (sensor cable, preliner, slipfilm, old pipe, soil, etc.). The mathematical model is designed so thatwith the aid of an equivalent thermal image, in consideration of thethermal energy delivered and the thermal resistance values, theresulting heat losses along the liner can be calculated. Based on theheat losses, the expected curing temperature in both the transverse andthe longitudinal direction of the liner can be ascertained. This resultis compared with the positional temperature distribution of the OWGsensors, so that conclusions as to local irregularities are possible.For example, if a local heat sink exists because of external water, theincrease in thermal energy can be back-calculated with the aid of themodel in order to compensate for the heat loss during curing. Thismethod is comparable with the real time temperature rating (RTTR) methodthat is used to calculate the thermal loads of energy cables.

In order to take into account the current (time-related) degree ofcuring during measurement for a calculation of the thermal resistancevalues of the liner resin, the temperature measurement system preferablyrecords the positional and time-related temperature profile of themeasurement locations. A depiction of the temperature values as afunction of measurement location and measurement repetition time is thetemperature image.

Explanations Regarding (b) Curing Quality

The temperature image further makes possible statements regarding thequality state along the liner. The measured profile over time can becompared, by software processing, with the predicted profile over time.The comparison shows whether there are locations along the liner whosecuring temperature lies outside a predefined tolerance band.

Explanations Regarding (c) Localization of Defect Sites

In the event of deficient liner quality, it is of interest to takesamples. TV-controlled mobile grinding robots, which are displaced inthe longitudinal direction of the conduit (liner), are generally usedfor sample removal. The coordinates for positioning the robot and thoseof the layout arrangement of the OWG sensors are generally different, sothat they are preferably coordinated with one another. Calibration ofthe sensor cable at known OWG sensor locations allows an allocation tothe measurement segment. In order to achieve more exact, more accuratepositioning of the grinding robot in the region of the damage site, aheat source (e.g. infrared radiator) is installed on the grinding robot;this induces a local heating in the sensors and produces a hot spot inthe positional temperature curve (see FIG. 4). The grinding robot iscontrolled so that the hot spot moves toward the temperature point wherethe damage site was identified. When the two temperature locationsagree, the sample can be taken.

Explanations Regarding (d) OWG Sensors

The disposition of OWG sensors (fibers or loose tubes or cables) takeaccount of the different temperature evolutions during curing(longitudinal and transverse arrangement of OWG sensors) and thegeometrical dimensions of the liner.

EXAMPLE 1

For heat-curing sleeves, the OWG sensors are preferably laid out on thelongitudinal axis of the inliner sleeve; for a pipe length of 100 m anda positional resolution of 1 m per horizontal sensor arrangement, 100temperature measurement points are therefore obtained.

For heat-curing methods, the OWG sensors are preferably positioned inthe region of the peak (12 o'clock position) and base (6 o'clockposition) in order to cover the temperature tolerance band of the curingprocess. With steam methods, the temperature in the base regionexperiences somewhat greater cooling, due to the formation ofcondensation, than in the peak region. With water methods, hot water istransported during the heating process through hoses from the supplyvehicle to the liner. Spatial temperature layers occur, in both thelongitudinal and the transverse direction of the liner, as the hot waterflows in. The water layers that form are somewhat warmer in the peakregion than in the base region.

EXAMPLE 2

A longitudinal arrangement can be selected for light-curing sleeves aswell. A transverse arrangement of OWG sensors offers the capability ofincreasing the density of measurement points in the region where thelight chain has a thermal effect. For a pipe diameter of 1 m, the sensorcable length is 3.14 m per circumference. With an average turn spacingof 25 cm and a pipe length of 100 m, approximately 400 turns with atotal OWG length of 1250 m can be installed. The user thus has more thana thousand measurement points available for controlling the curingprocess.

An OWG sensor can be embodied as a sensor cable, sensor fiber, or sensormat. The structure of the sensor cable is usually made up of a sheathedloose tube (stainless-steel or plastic tube) having at least oneintegrated OWG sensor fiber. The diameter of the sensor cable istypically 4 to 5 mm. As a result of the loose tube construction, sensorcables have a relatively high rigidity that makes installation ontosmall surfaces difficult or impossible. For this reason, the OWG sensorcable (see FIG. 5 b) is preferably positioned between the old pipe andthe preliner/slip film (see FIG. 5 a) or between the preliner/slip filmand the liner.

When an OWG sensor is integrated into the preliner/slip film or directlyinto the liner (see FIG. 5 c), an OWG loose tube having a small diameter(between 0.8 mm and 2 mm) and with a built-in fiber or an OWG fiber (seeFIG. 5 d) is preferable. Because the OWG sensor elements in the linerare exposed to large mechanical compressive and tensile forces duringrehabilitation, a suitable type of OWG that is insensitive tomicrocurvature is preferable. So-called multimode fibers, having a largecore diameter (62.5 .mu.m and larger) and a large jacket diameter (500.mu.m), are preferred. The OWG fiber can be given additional mechanicalprotection with a loose tube (made e.g. of plastic or stainless steel),with the advantage of compensating for thermal material expansion of theOWG fiber with respect to its environment. In order to ensure goodmechanical protection during the rehabilitation operation, the OWG fiberis connected to a robust OWG sensor cable using a splice connection.

A further embodiment of an OWG sensor is an OWG sensor mat (see FIGS. 5f and 5 h). The sensor mat concept enables integration of the OWG sensorfiber into a glass-fiber textile with good mechanical protection, andinstallation between the old pipe and the preliner or slip film (seeFIGS. 5 e and 5 g). In addition, with an OWG sensor mat, an additionallength of the OWG sensors

a) can be introduced in a circumferential direction (see FIG. 5 f) inorder to increase positional accuracy in the transverse direction of theliner;

b) introduced in a horizontal direction (see FIG. 5 i) in order toincrease positional accuracy in the longitudinal direction of the liner.

In order to meet mechanical requirements when the sensor mat isinstalled between an old pipe and a preliner or slip film, the sensormat includes a hard underlayer facing toward the old pipe, and a softupper layer facing toward the preliner or slip film.

The sensor mat is preferably fabricated using a type of OWG that isinsensitive to microcurvature, so that when the OWG sensor fiber isembedded into the composite material (direct embedding or in combinationwith a loose tube), the additional losses remain tolerable andcorrectable. To ensure good mechanical protection, the OWG fiber isattached to a robust OWG sensor cable using a splice connection (seeFIGS. 5 f and 5 h).

With walkable conduits, the possibility exists of mounting the OWGsensor (sensor cable, sensor fiber, or sensor mat) on the old pipe.

Explanations Regarding (e1) Leak Detection

When conduits are rehabilitated, unsealed sites can occur that can causea washout beneath the conduit. These leaks are undesirable, and aredifficult to localize.

The water flowing through the conduit generally has a higher temperaturethan the outside temperature of the inliner sleeve, and a highertemperature than groundwater temperature. The positional temperatureprofile in the longitudinal direction of the conduit is almost constant(only a small positional temperature gradient). At a leak, the conduitwater flows through the sheathing to the base of the inliner sleeve. Ifthe sensor cable is mounted below the inliner sleeve (6 o'clockposition, between the concrete pipe and inliner sleeve, see FIG. 2), itis possible to locate leaks by temperature measurement. Leaks cause alocal deviation in the positional temperature gradient, so that theseunsealed sites can be localized.

Explanations Regarding (e2) Liquid Level Measurement

A variety of methods are used in the waste water sector to measure waterlevel. The greatest problem is that contaminants yield inaccurate anddefective readings.

A sensor mat concept (see FIGS. 5 f and 5 h), as well as horizontal OWGsensor arrangements (see FIG. 1 d), can be used for liquid levelmeasurement in the conduit. By evaluating the positional temperaturevalues, the water height can be ascertained based on the differingtemperatures of the flowing medium and air. The advantages of the OWGtechnique include:

no risk of explosion, since the sensor is passive;

no need to supply power;

little change in cross section when installed at a later date;

planar measurement distribution, therefore insensitive to corrugations;

multiple measurements possible with one cable.

Explanations Regarding (e3) Temperature Image Measurement

Every day, large quantities of waste water are transported through wastewater conduit systems, purified in treatment plants, and then introducedinto drainage outfalls. This represents essentially a waste product withno economic value. The waste water from residences and from agriculturaland industrial operations not only carries off hazardous substances,however, but also causes heating of the water. The waste water thatflows off is therefore at a higher temperature than, for example,drinking water.

There is increasing interest in utilizing this energy potential of wastewater to provide heat, i.e. to heat premises and provide them with hotwater. The input of heated water is not constant, but is dependent onmany factors (time of year, work schedules, productivity levels, inflowsand outflows). Optimization of the heat exchange process typicallyutilizes an in situ measurement of water heating. The OWG sensorarrangements and embodiments according to the present invention aresuitable for measuring temperature distribution in the waste waterconduit.

Further features of the present invention are recited below. Thefeatures can be implemented individually or together

The fiber optic sensor can be introduced as an OWG sensor cable.

The fiber optic sensor is preferably introduced in a mat, the planarintroduction being accomplished in a meander shape. The loops of themeander can be introduced parallel to the longitudinal extension of themat, or perpendicular to the longitudinal extension of the mat.

The positionally resolved image of temperature as a function of locationand time (hereinafter referred to simply as a “temperature image”) iscreated during installation (during the curing operation) of the sleeveor lining. The delivery of energy (light and/or heat) to the lining ismonitored during curing. Supervision and monitoring of the curingprocess occur.

The temperature image can be brought into correlation with a thermalmodel of the system. The temperature image can further be brought intocorrelation with a definable temperature tolerance band. Based on thetemperature image, local deviations between measured and predictedcuring temperatures can be identified

The local deviations identified can be used to control a robot that isdisplaced along the lined pipe or conduit system, for example for theremoval of samples.

For performance of the measurement method, the at least one fiber opticsensor is preferably introduced between the lining and the old pipe.

At least one optical waveguide sensor cable, or an optical waveguidesensor mat, is then located between the liner and the old pipe. Thesensor mat preferably includes a plastic or glass-fiber textile having ahard underside (on the inside, toward the conduit) and a soft upper side(on the outside, toward the old pipe), into which the optical waveguidesensor fiber is introduced directly or in combination with a loose tube.

Alternatively to the embodiment recited, the at least one fiber opticsensor can be located on the old pipe, or inside a preliner or a slipfilm or a liner.

A factor for controlling the process parameters for the action of heaton the liner is whether the OWG sensor is positioned or introduced onthe inner side of the lining (toward the center of the conduit) or onthe outer side (toward the old pipe). Temperature differences of 5 to 10K between inside and outside can easily occur due to the relatively lowthermal conductivity of a glass-fiber-reinforced sleeve, or as a resultof contact externally with the old pipe and the heat dissipationassociated therewith.

The fiber optic temperature sensor apparatus can be used forpositionally resolved water level measurement in pipe and conduitsystems, and to measure waste water temperature.

The fiber optic temperature sensor apparatus that is used can be used inthe form of a Raman temperature sensor apparatus.

FIG. 1 schematically shows the arrangements for measuring curing statusduring conduit rehabilitation, utilizing fiber optic temperaturemeasurement. FIG. 1 a shows a liner 2 installed in conduit 1. Thermalenergy 22 for curing of the liner is delivered from supply vehicle 21through shaft 12. Sensor cable 3, on the other hand, was installed fromthe oppositely located shaft 11. The example depicted shows a sensorarrangement in the form of a stub line. The optical measurement signalis generated in evaluation device 31 (optical backscatter measurementdevice) and coupled into the sensor cable (optical waveguide, OWG). Thelight backscattered out of the OWG can be used in known fashion forpositionally distributed temperature measurement. The sensor cable isarranged so that the positional temperature graph (FIG. 1 b and FIG. 1c) of the individual measurement represents the temperature along theOWG supply lead (up to approx. the 150 m location point) and along theshaft region (between 150 m and 365 m), and the temperature distributionalong the base region (between 235 m and 365 m) and the peak region(between 365 m and 495 m) of the liner. The permissible temperaturetolerance band 43 for the curing process of the particular formulationcan be implemented in the software-based evaluation and presentation ofthe positional temperature curves, so that irregularities can berecognized, assessed, and localized. Irregularities resulting from, forexample, local inflows of outside water 41 or local overheating spots 42are depicted in the measured temperature curves of FIG. 1 b and FIG. 1 c

FIG. 1 d shows a sensor arrangement in which OWG sensor 3 is positionedin a horizontal direction with respect to the liner in order to achievea high measurement density in the longitudinal direction of the liner.At each end of liner 2, the OWG is turned back in the form of loops 36.Longitudinal arrangements of OWG sensor 34 are preferably used forheat-curing liners. FIG. 1 e shows a sensor arrangement in which OWGsensor 3 is positioned in a circumferential direction with respect tothe liner in order to achieve a high measurement density in transversedirection 35 of the liner. Transverse arrangements of OWG sensor 35 arepreferably used for light-curing liners.

FIG. 2 shows an apparatus for controlling the liner curing process, incombination with a fiber optic temperature measurement using a thermalmodel. Sensor cable 3 is installed over two reaches (three shafts) eachhaving a stub line for the peak region 32 and a stub line for baseregion 33 of liner 2. Based on the positional and time-related measuredtemperature data of the OWG sensor (thermographic image 37), evaluationdevice 31 calculates the present thermal resistance of the liner resin.These data are made available, together with the thermal energy being(at present) delivered, to a thermal model 38 for further calculation.The thermal energy delivered can be ascertained, for example(indirectly) from process parameters 23 of the thermal energy supplysystem or (directly) by measuring the process temperature. The input ofthermal energy 22 is raised or lowered in accordance with the result ofthe dynamic thermal model.

FIG. 3 is intended to elucidate correlations with regard to statementsabout liner quality. The graphs of FIGS. 3 a to 3 c refer to theschematic arrangement of FIG. 1 a, and show the temperature profileduring curing of a liner in various presentation forms. FIG. 3 arepresents, inter alia, the positional temperature profile in shaftregion 55 and in conduit region 51 at a specific measurement time (t=305min with respect to measurement start). The time profiles of thepositional points (52, 53, and 56) marked in FIG. 3 a are depicted inFIG. 3 b over the entire measurement time period (600 min). The regionof the liner at positional point 52 shows a time-related irregularity inthe form of a short-term elevation at measurement time t=305 min. Noirregularity exists at positional point 53, but a lower curingtemperature is achieved at this site than at site 52. Temperatureprofile 56 over time shows only the ambient temperature in accordancewith prevailing weather conditions (diurnal profile) at the shaft inlet.FIG. 3 c represents the capability for a thermographic depiction of thetemperature profile as a function of position and time.

FIG. 4 refers to the problem of taking samples using a grinding robot,and shows an apparatus for positioning a grinding robot. When qualitydefects 4 on the liner are identified, a sample is taken from liner 2using a grinding robot 24. Positioning of the grinding robot isperformed, for example, from supply vehicle 21. In order to achieve themost exact positioning possible, the grinding robot possesses a heatsource 25. The distance of the temperature location of heat source 25from the temperature location of the damage site can be calculated usingsoftware. Based on the result of a coordinate adjustment 39, thegrinding robot is repositioned until the exact site for taking a sampleis found.

FIGS. 5 a to 5 h show examples, in the form of schematic depictions, ofvarious arrangements and embodiments of the OWG sensor for use in pipeand conduit systems utilizing sleeve-lining methods.

The OWG sensor can be embodied as an OWG sensor cable 61 (see FIG. 5 b),as an OWG sensor fiber 64 (see FIG. 5 d), or as an OWG sensor mat 62, 63(see FIGS. 5 f and 5 h). The OWG sensor is arranged depending on theconfiguration of the conduit and whether it is walkable. OWG sensorcable 61 is preferably positioned between old pipe/conduit 1 andpreliner/slip film 26 (see FIG. 5 a); OWG sensor fiber 64, on the otherhand, is suitable for integration into liner 2 (see FIG. 5 c), and OWGsensor mat 62, 63 is preferably installed between the old pipe and thepreliner/slip film (see FIGS. 5 e and 5 g). For walkable conduits, allthe OWG sensor versions can be mounted on the old pipe. The sensor matconcept allows the positional accuracy of the sensor measurement systemto be increased by introducing, based on a selectable length ratio 66,an additional length of OWG sensor cable in the longitudinal directionof the liner (see FIG. 5 h) or in the transverse direction (see FIG. 5f). In order to ensure good mechanical protection during therehabilitation operation, OWG sensor fiber 64 is attached to a robustOWG sensor cable 61 using a splice connection 65.

FIG. 6 shows an example of a sensor mat embodiment having a boot 67 forliquid level measurement in the shaft region. In order to increasepositional accuracy in the vertical direction (water level direction),OWG fiber 64 is arranged in a meander shape. The sensor mat contains asplice cassette 68 to enable easy and rapid installation in the conduit.To ensure good mechanical protection, OWG sensor fiber 64 is attached toa robust OWG sensor cable 61 using a splice connection 65.

The present invention is not limited to the embodiments describedherein; reference should be had to the appended claims.

SUMMARY OF REFERENCES IN THE FIGURES

1 Conduit

11 Shaft A

12 Shaft B

2 Liner

21 Supply vehicle

22 Input of thermal energy

23 Process parameters

24 Grinding robot

25 Heat source

26 Preliner/slip film

27 Outer side of liner

28 Inner side of liner

3 OWG sensor

31 Fiber-optic evaluation device

32 OWG in peak region

33 OWG in base region

34 OWG in longitudinal direction

35 OWG in transverse direction

36 OWG loop

37 Thermographic image

38 Thermal model

39 Coordinate adjustment

4 Irregularities

41 Overheating

42 Outside water

43 Temperature tolerance band

51 Conduit region (CR)

52 Measurement location 1 in CR

53 Measurement location 2 in CR

54 Measurement location 3 in CR

55 Shaft region (SR)

56 Measurement location 1 in SR

61 OWG cable 62 OWG sensor mat (longitudinal type)

63 OWG sensor mat (transverse type)

64 OWG sensor fiber

65 OWG splice connection

66 Length ratio

67 OWG sensor mat with boot

68 OWG splice cassette

7 Water level

1. A method for monitoring a status of a sleeve lining in a pipe orconduit, wherein the sleeve comprises a curable resin, the methodcomprising the steps of: disposing a fiber optic sensor arrangement inthermally conductive contact with the sleeve, wherein the fiber opticsensor arrangement is configured to sense the temperature of the sleevealong multiple positions along the length thereof; curing the curableresin over a period of time; during the curing act, generating, usingthe fiber optic sensor arrangement, positional and time-related measureddata of the temperature thereof; wherein the act of generatingpositional and time-related measured data is performed using apositionally distributed temperature sensing system.
 2. The method asrecited in claim 1, wherein the step of generating positional andtime-related measured data is reiterated during the curing act.
 3. Themethod as recited in claim 1, and further comprising a step ofrepetition of the act of generating positional and time-related measureddata of the temperature of the sleeve through operating period of thesleeve.
 4. The method as recited in claim 1, and further comprisingverification of curing quality of the sleeve following generatingpositional and time-related measured data of the temperature of multiplepositions along length of the sleeve.
 5. The method as recited in claim1, and further comprising recording positional and time-related measureddata of the temperature of the sleeve.
 6. The method as recited in claim5, and further comprising depicting positional and time-related measureddata of the temperature of the sleeve.
 7. The method as recited in claim6, wherein the depiction represents positional and time-related measureddata of the temperature at a positional resolution below 1 m.
 8. Themethod as recited in claim 6, wherein the depiction of the positionaland time-related measured data represents selected positions along thesleeve.
 9. The method as recited in claim 6, wherein the depiction ofthe positional and time-related measured data along the sleeve is afunction of time.
 10. The method as recited in claim 6, wherein thedepiction of the positional and time-related measured data is a3-dimentional representation.
 11. The method as recited in claim 1,further comprising the step of correlating the positional andtime-related data with a thermal model of the curable resin as afunction of the degree of curing.
 12. The method as recited in claim 1,whereby the positional and time-related measured data can be used tocontrol the energy for the curing process.
 13. A system configured tomonitor a status of a sleeve lining in a pipe or conduit, wherein thesleeve comprises a curable resin, the system comprising: a fiber opticsensor arrangement disposed in thermally conductive contact with thesleeve, wherein the fiber optic sensor arrangement is configured tosense the temperature of the sleeve along multiple positions along thelength thereof; a thermal energy source or a light source coupled to thepipe or conduit for curing the curable resin over a period of time; andan evaluation apparatus coupled to the fiber optic sensor arrangementand configured to generate, using the fiber optic sensor arrangement,positional and time-related measured data representative of atemperature of the sleeve as a function of multiple positions along thelength thereof and over a period of time; whereby the fiber optic sensorarrangement comprises at least one optical waveguide.
 14. The system asrecited in claim 13, wherein the multiple positions are about 0.5 m toabout 1 m along the length of the sleeve.
 15. The system as recited inclaim 13, wherein the fiber optic sensor arrangement comprises amultimode optical fiber.
 16. The system as recited in claim 13, whereinthe at least one optical waveguide is embodied as an optical waveguidesensor cable.
 17. A method for monitoring a status of a sleeve lining ina pipe or conduit, wherein the sleeve comprises a curable resin, themethod comprising the steps of: disposing a fiber optic sensorarrangement in thermally conductive contact with the sleeve, wherein thefiber optic sensor arrangement is configured to sense the temperature ofthe sleeve along multiple positions along the length thereof; curing thecurable resin over a period of time; during the curing act, generating,using the fiber optic sensor arrangement, positional and time-relatedmeasured data of the temperature thereof; wherein the act of generatingpositional and time-related measured data is performed using apositionally distributed temperature sensing system.
 18. The method asrecited in claim 17, wherein the step of generating positional andtime-related measured data is reiterated during the curing act.
 19. Themethod as recited in claim 17, and further comprising a step ofrepetition of the act of generating positional and time-related measureddata of the temperature of the sleeve through operating period of thesleeve.
 20. The method as recited in claim 17, and further comprisingverification of curing quality of the sleeve following generatingpositional and time-related measured data of the temperature of multiplepositions along length of the sleeve.
 21. The method as recited in claim17, and further comprising recording positional and time-relatedmeasured data of the temperature of the sleeve.
 22. The method asrecited in claim 21, and further comprising depicting positional andtime-related measured data of the temperature of the sleeve.
 23. Themethod as recited in claim 22, wherein the depiction representspositional and time-related measured data of the temperature at smallestdistances of spatial positional points.
 24. The method as recited inclaim 22, wherein the depiction of the positional and time-relatedmeasured data represents selected positions along the sleeve.
 25. Themethod as recited in claim 22, wherein the depiction of the positionaland time-related measured data along the sleeve is a function of time.26. The method as recited in claim 22, wherein the depiction of thepositional and time-related measured data is a 3-dimentionalrepresentation.
 27. The method as recited in claim 17, furthercomprising the step of correlating the positional and time-related datawith a thermal model of the curable resin as a function of the degree ofcuring.
 28. The method as recited in claim 17, whereby the positionaland time-related measured data can be used to control the energy for thecuring process.
 29. A system configured to monitor a status of a sleevelining in a pipe or conduit, wherein the sleeve comprises a curableresin, the system comprising: a fiber optic sensor arrangement disposedin thermally conductive contact with the sleeve, wherein the fiber opticsensor arrangement is configured to sense the temperature of the sleevealong multiple positions along the length thereof; a thermal energysource or a light source coupled to the pipe or conduit for curing thecurable resin over a period of time; and an evaluation apparatus coupledto the fiber optic sensor arrangement and configured to generate, usingthe fiber optic sensor arrangement, positional and time-related measureddata representative of a temperature of the sleeve as a function ofmultiple positions along the length thereof and over a period of time;whereby the fiber optic sensor arrangement comprises at least oneoptical waveguide.
 30. The system as recited in claim 29, wherein themultiple positions are about 0.5 m to about 1 m along the length of thesleeve.
 31. The system as recited in claim 29, wherein the fiber opticsensor arrangement comprises a multimode optical fiber.
 32. The systemas recited in claim 29, wherein the at least one optical waveguide isembodied as an optical waveguide sensor cable.